I started swim training for triathlon in December and was shocked to discover how poor a swimmer I was. For my first tri last month I had to do a 300m pool swim. I was just to the point where I could do 400m of straight freestyle. I was doing the 300m in just under 6 minutes. At the event I lost all my composure and it took me 7:20. For Iron Girl this last weekend I had a 1000m OWS. I could do the distance in the pool, but had to mix in side stroke to rest and catch up on my breathing. What took me about 22-24 minutes in the pool took 28 minutes OWS. I knew it was going to be long and ugly but I knew I could do the distance one stroke or the other. Unless you are a really fast learner you are going to have to accept that it will be long and ugly. If you have the confidence that you can safely do the distance in one stroke or another, then go for it.